git.m6w6.name Git - awesomized/libmemcached/blob - docs/bin/memaslap.rst

   1 ==================================================
   2 memaslap - Load testing  and benchmarking a server
   3 ==================================================
   4
   5
   6 --------
   7 SYNOPSIS
   8 --------
   9
  10 memaslap [options]
  11
  12 .. program:: memaslap
  13
  14 .. option:: --help
  15
  16 -----------
  17 DESCRIPTION
  18 -----------
  19
  20
  21 :program:`memaslap` is a load generation and benchmark tool for memcached
  22 servers. It generates configurable workload such as threads, concurrencies,
  23 connections, run time, overwrite, miss rate, key size, value size, get/set
  24 proportion, expected throughput, and so on. Furthermore, it also testss data
  25 verification, expire-time verification, UDP, binary protocol, facebook test,
  26 replication test, multi-get and reconnection, etc.
  27
  28 Memaslap manages network connections like memcached with
  29 libevent. Each thread of memaslap is bound with a CPU core, all
  30 the threads don't communicate with each other, and there are several socket
  31 connections in each thread. Each connection keeps key size distribution,
  32 value size distribution, and command distribution by itself.
  33
  34 You can specify servers via the :option:`--servers` option or via the
  35 environment variable :envvar:`MEMCACHED_SERVERS`.
  36
  37
  38 --------
  39 FEATURES
  40 --------
  41
  42
  43 Memslap is developed to for the following purposes:
  44
  45
  46 Manages network connections with libevent asynchronously.
  47
  48
  49
  50 Set both TCP and UDP up to use non-blocking IO.
  51
  52
  53
  54 Improves parallelism: higher performance in multi-threads environments.
  55
  56
  57
  58 Improves time efficiency: faster processing speed.
  59
  60
  61
  62 Generates key and value more efficiently; key size distribution and value size distribution are configurable.
  63
  64
  65
  66 Supports get, multi-get, and set commands; command distribution is configurable.
  67
  68
  69
  70 Supports controllable miss rate and overwrite rate.
  71
  72
  73
  74 Supports data and expire-time verification.
  75
  76
  77
  78 Supports dumping statistic information periodically.
  79
  80
  81
  82 Supports thousands of TCP connections.
  83
  84
  85
  86 Supports binary protocol.
  87
  88
  89
  90 Supports facebook test (set with TCP and multi-get with UDP) and replication test.
  91
  92
  93
  94
  95 -------
  96 DETAILS
  97 -------
  98
  99
 100 Effective implementation of network.
 101 ____________________________________
 102
 103
 104 For memaslap, both TCP and UDP use non-blocking network IO. All
 105 the network events are managed by libevent as memcached. The network module
 106 of memaslap is similar to memcached. Libevent can ensure
 107 memaslap can handle network very efficiently.
 108
 109
 110 Effective implementation of multi-threads and concurrency
 111 _________________________________________________________
 112
 113
 114 Memslap has the similar implementation of multi-threads to
 115 memcached. Memslap creates one or more self-governed threads;
 116 each thread is bound with one CPU core if the system testss setting CPU
 117 core affinity.
 118
 119 In addition, each thread has a libevent to manage the events of the network;
 120 each thread has one or more self-governed concurrencies; and each
 121 concurrency has one or more socket connections. All the concurrencies don’t
 122 communicate with each other even though they are in the same thread.
 123
 124 Memslap can create thousands of socket connections, and each
 125 concurrency has tens of socket connections. Each concurrency randomly or
 126 sequentially selects one socket connection from its socket connection pool
 127 to run, so memaslap can ensure each concurrency handles one
 128 socket connection at any given time. Users can specify the number of
 129 concurrency and socket connections of each concurrency according to their
 130 expected workload.
 131
 132
 133 Effective implementation of generating key and value
 134 ____________________________________________________
 135
 136
 137 In order to improve time efficiency and space efficiency,
 138 memaslap creates a random characters table with 10M characters. All the
 139 suffixes of keys and values are generated from this random characters table.
 140
 141 Memslap uses the offset in the character table and the length
 142 of the string to identify a string. It can save much memory.
 143 Each key contains two parts, a prefix and a suffix. The prefix is an
 144 uint64_t, 8 bytes. In order to verify the data set before,
 145 memaslap need to ensure each key is unique, so it uses the prefix to identify
 146 a key. The prefix cannot include illegal characters, such as ‘\r’, ‘\n’,
 147 ‘\0’ and ‘ ‘. And memaslap has an algorithm to ensure that.
 148
 149 Memslap doesn’t generate all the objects (key-value pairs) at
 150 the beginning. It only generates enough objects to fill the task window
 151 (default 10K objects) of each concurrency. Each object has the following
 152 basic information, key prefix, key suffix offset in the character table, key
 153 length, value offset in the character table, and value length.
 154
 155 In the work process, each concurrency sequentially or randomly selects an
 156 object from the window to do set operation or get operation. At the same
 157 time, each concurrency kicks objects out of its window and adds new object
 158 into it.
 159
 160
 161 Simple but useful task scheduling
 162 _________________________________
 163
 164
 165 Memslap uses libevent to schedule all the concurrencies of
 166 threads, and each concurrency schedules tasks based on the local task
 167 window. Memslap assumes that if each concurrency keeps the same
 168 key distribution, value distribution and commands distribution, from
 169 outside, memaslap keeps all the distribution as a whole.
 170 Each task window includes a lot of objects, each object stores its basic
 171 information, such as key, value, expire time, and so on. At any time, all
 172 the objects in the window keep the same and fixed key and value
 173 distribution. If an object is overwritten, the value of the object will be
 174 updated. Memslap verifies the data or expire-time according to
 175 the object information stored in the task window.
 176
 177 Libevent selects which concurrency to handle based on a specific network
 178 event. Then the concurrency selects which command (get or set) to operate
 179 based on the command distribution. If it needs to kick out an old object and
 180 add a new object, in order to keep the same key and value distribution, the
 181 new object must have the same key length and value length.
 182
 183 If memcached server has two cache layers (memory and SSD), running
 184 memaslap with different window sizes can get different cache
 185 miss rates. If memaslap adds enough objects into the windows at
 186 the beginning, and the cache of memcached cannot store all the objects
 187 initialized, then memaslap will get some objects from the second
 188 cache layer. It causes the first cache layer to miss. So the user can
 189 specify the window size to get the expected miss rate of the first cache
 190 layer.
 191
 192
 193 Useful implementation of multi-servers , UDP, TCP, multi-get and binary protocol
 194 ________________________________________________________________________________
 195
 196
 197 Because each thread is self-governed, memaslap can assign
 198 different threads to handle different memcached servers. This is just one of
 199 the ways in which memaslap tests multiple servers. The only
 200 limitation is that the number of servers cannot be greater than the number
 201 of threads. The other way to test multiple servers is for replication
 202 test. Each concurrency has one socket connection to each memcached server.
 203 For the implementation, memaslap can set some objects to one
 204 memcached server, and get these objects from the other servers.
 205
 206 By default, Memslap does single get. If the user specifies
 207 multi-get option, memaslap will collect enough get commands and
 208 pack and send the commands together.
 209
 210 Memslap testss both the ASCII protocol and binary protocol,
 211 but it runs on the ASCII protocol by default.
 212 Memslap by default runs on the TCP protocol, but it also
 213 tests UDP. Because UDP is unreliable, dropped packages and out-of-order
 214 packages may occur. Memslap creates a memory buffer to handle
 215 these problems. Memslap tries to read all the response data of
 216 one command from the server and reorders the response data. If some packages
 217 get lost, the waiting timeout mechanism can ensure half-baked packages will
 218 be discarded and the next command will be sent.
 219
 220
 221
 222 -----
 223 USAGE
 224 -----
 225
 226
 227 Below are some usage samples:
 228
 229
 230 memaslap -s 127.0.0.1:11211 -S 5s
 231
 232
 233
 234 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
 235
 236
 237
 238 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
 239
 240
 241
 242 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
 243
 244
 245
 246 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
 247
 248
 249
 250 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
 251
 252
 253
 254 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
 255
 256
 257
 258 The user must specify one server at least to run memaslap. The
 259 rest of the parameters have default values, as shown below:
 260
 261 Thread number = 1                    Concurrency = 16
 262
 263 Run time = 600 seconds                Configuration file = NULL
 264
 265 Key size = 64                         Value size = 1024
 266
 267 Get/set = 9:1                         Window size = 10k
 268
 269 Execute number = 0                   Single get = true
 270
 271 Multi-get = false                      Number of sockets of each concurrency = 1
 272
 273 Reconnect = false                     Data verification = false
 274
 275 Expire-time verification = false           ASCII protocol = true
 276
 277 Binary protocol = false                 Dumping statistic information
 278
 279 periodically = false
 280
 281 Overwrite proportion = 0%             UDP = false
 282
 283 TCP = true                           Limit throughput = false
 284
 285 Facebook test = false                  Replication test = false
 286
 287 Key size, value size and command distribution.
 288 ______________________________________________
 289
 290
 291 All the distributions are read from the configuration file specified by user
 292 with “—cfg_cmd” option. If the user does not specify a configuration file,
 293 memaslap will run with the default distribution (key size = 64,
 294 value size = 1024, get/set = 9:1). For information on how to edit the
 295 configuration file, refer to the “Configuration File” section.
 296
 297 The minimum key size is 16 bytes; the maximum key size is 250 bytes. The
 298 precision of proportion is 0.001. The proportion of distribution will be
 299 rounded to 3 decimal places.
 300
 301 The minimum value size is 1 bytes; the maximum value size is 1M bytes. The
 302 precision of proportion is 0.001. The proportion of distribution will be
 303 rounded to 3 decimal places.
 304 Currently, memaslap only testss set and get commands. And it
 305 testss 100% set and 100% get. For 100% get, it will preset some objects to
 306 the server.
 307
 308
 309 Multi-thread and concurrency
 310 ____________________________
 311
 312
 313 The high performance of memaslap benefits from the special
 314 schedule of thread and concurrency. It’s important to specify the proper
 315 number of them. The default number of threads is 1; the default number of
 316 concurrency is 16. The user can use “—threads” and “--concurrency” to
 317 specify these variables.
 318
 319 If the system tests setting CPU affinity and the number of threads
 320 specified by the user is greater than 1, memaslap will try to
 321 bind each thread to a different CPU core. So if you want to get the best
 322 performance memaslap, it is better to specify the number of
 323 thread equal to the number of CPU cores. The number of threads specified by
 324 the user can also be less or greater than the number of CPU cores. Because
 325 of the limitation of implementation, the number of concurrencies could be
 326 the multiple of the number of threads.
 327
 328 1. For 8 CPU cores system
 329
 330 For example:
 331
 332 --threads=2 --concurrency=128
 333
 334 --threads=8 --concurrency=128
 335
 336 --threads=8 --concurrency=256
 337
 338 --threads=12 --concurrency=144
 339
 340 2. For 16 CPU cores system
 341
 342 For example:
 343
 344 --threads=8 --concurrency=128
 345
 346 --threads=16 --concurrency=256
 347
 348 --threads=16 --concurrency=512
 349
 350 --threads=24 --concurrency=288
 351
 352 The memaslap performs very well, when
 353 used to test the performance of memcached servers.
 354 Most of the time, the bottleneck is the network or
 355 the server. If for some reason the user wants to
 356 limit the performance of memaslap, there
 357 are two ways to do this:
 358
 359 Decrease the number of threads and concurrencies.
 360 Use the option “--tps” that memaslap
 361 provides to limit the throughput. This option allows
 362 the user to get the expected throughput. For
 363 example, assume that the maximum throughput is 50
 364 kops/s for a specific configuration, you can specify
 365 the throughput equal to or less than the maximum
 366 throughput using “--tps” option.
 367
 368
 369 Window size
 370 ___________
 371
 372
 373 Most of the time, the user does not need to specify the window size. The
 374 default window size is 10k. For Schooner Memcached, the user can specify
 375 different window sizes to get different cache miss rates based on the test
 376 case. Memslap testss cache miss rate between 0% and 100%.
 377 If you use this utility to test the performance of Schooner Memcached, you
 378 can specify a proper window size to get the expected cache miss rate. The
 379 formula for calculating window size is as follows:
 380
 381 Assume that the key size is 128 bytes, and the value size is 2048 bytes, and
 382 concurrency=128.
 383
 384 1. Small cache cache_size=1M, 100% cache miss (all data get from SSD).
 385 win_size=10k
 386
 387 2. cache_size=4G
 388
 389 (1). cache miss rate 0%
 390
 391 win_size=8k
 392
 393 (2). cache miss rate 5%
 394
 395 win_size=11k
 396
 397 3. cache_size=16G
 398
 399 (1). cache miss rate 0%
 400
 401 win_size=32k
 402
 403 (2). cache miss
 404
 405 rate 5%
 406
 407 win_size=46k
 408
 409 The formula for calculating window size for cache miss rate 0%:
 410
 411 cache_size / concurrency / (key_size + value_size) \* 0.5
 412
 413 The formula for calculating window size for cache miss rate 5%:
 414
 415 cache_size / concurrency / (key_size + value_size) \* 0.7
 416
 417
 418 Verification
 419 ____________
 420
 421
 422 Memslap testss both data verification and expire-time
 423 verification. The user can use "--verify=" or "-v" to specify the proportion
 424 of data verification. In theory, it testss 100% data verification. The
 425 user can use "--exp_verify=" or "-e" to specify the proportion of
 426 expire-time verification. In theory, it testss 100% expire-time
 427 verification. Specify the "--verbose" options to get more detailed error
 428 information.
 429
 430 For example: --exp_verify=0.01 –verify=0.1 , it means that 1% of the objects
 431 set with expire-time, 10% of the objects gotten will be verified. If the
 432 objects are gotten, memaslap will verify the expire-time and
 433 value.
 434
 435
 436 multi-servers and multi-config
 437 _______________________________
 438
 439
 440 Memslap testss multi-servers based on self-governed thread.
 441 There is a limitation that the number of servers cannot be greater than the
 442 number of threads. Memslap assigns one thread to handle one
 443 server at least. The user can use the "--servers=" or "-s" option to specify
 444 multi-servers.
 445
 446 For example:
 447
 448 --servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 --threads=6 --concurrency=36
 449
 450 The above command means that there are 6 threads, with each thread having 6
 451 concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1
 452 and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2
 453 (10.1.1.3).
 454
 455 All the threads and concurrencies in memaslap are self-governed.
 456
 457 So is memaslap. The user can start up several
 458 memaslap instances. The user can run memaslap on different client
 459 machines to communicate with the same memcached server at the same. It is
 460 recommended that the user start different memaslap on different
 461 machines using the same configuration.
 462
 463
 464 Run with execute number mode or time mode
 465 _________________________________________
 466
 467
 468 The default memaslap runs with time mode. The default run time
 469 is 10 minutes. If it times out, memaslap will exit. Do not
 470 specify both execute number mode and time mode at the same time; just
 471 specify one instead.
 472
 473 For example:
 474
 475 --time=30s (It means the test will run 30 seconds.)
 476
 477 --execute_number=100000 (It means that after running 100000 commands, the test will exit.)
 478
 479
 480 Dump statistic information periodically.
 481 ________________________________________
 482
 483
 484 The user can use "--stat_freq=" or "-S" to specify the frequency.
 485
 486 For example:
 487
 488 --stat_freq=20s
 489
 490 Memslap will dump the statistics of the commands (get and set) at the frequency of every 20
 491 seconds.
 492
 493 For more information on the format of dumping statistic information, refer to “Format of Output” section.
 494
 495
 496 Multi-get
 497 _________
 498
 499
 500 The user can use "--division=" or "-d" to specify multi-get keys count.
 501 Memslap by default does single get with TCP. Memslap also testss data
 502 verification and expire-time verification for multi-get.
 503
 504 Memslap testss multi-get with both TCP and UDP. Because of
 505 the different implementation of the ASCII protocol and binary protocol,
 506 there are some differences between the two. For the ASCII protocol,
 507 memaslap sends one “multi-get” to the server once. For the
 508 binary protocol, memaslap sends several single get commands
 509 together as “multi-get” to the server.
 510
 511
 512 UDP and TCP
 513 ___________
 514
 515
 516 Memslap testss both UDP and TCP. For TCP,
 517 memaslap does not reconnect the memcached server if socket connections are
 518 lost. If all the socket connections are lost or memcached server crashes,
 519 memaslap will exit. If the user specifies the “--reconnect”
 520 option when socket connections are lost, it will reconnect them.
 521
 522 User can use “--udp” to enable the UDP feature, but UDP comes with some
 523 limitations:
 524
 525 UDP cannot set data more than 1400 bytes.
 526
 527 UDP is not testsed by the binary protocol because the binary protocol of
 528 memcached does not tests that.
 529
 530 UDP doesn’t tests reconnection.
 531
 532
 533 Facebook test
 534 _____________
 535
 536
 537 Set data with TCP and multi-get with UDP. Specify the following options:
 538
 539 "--facebook --division=50"
 540
 541 If you want to create thousands of TCP connections, specify the
 542
 543 "--conn_sock=" option.
 544
 545 For example: --facebook --division=50 --conn_sock=200
 546
 547 The above command means that memaslap will do facebook test,
 548 each concurrency has 200 socket TCP connections and one UDP socket.
 549
 550 Memslap sets objects with the TCP socket, and multi-gets 50
 551 objects once with the UDP socket.
 552
 553 If you specify "--division=50", the key size must be less that 25 bytes
 554 because the UDP packet size is 1400 bytes.
 555
 556
 557 Replication test
 558 ________________
 559
 560
 561 For replication test, the user must specify at least two memcached servers.
 562 The user can use “—rep_write=” option to enable feature.
 563
 564 For example:
 565
 566 --servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
 567
 568 The above command means that there are 2 replication memcached servers,
 569 memaslap will set objects to both server 0 and server 1, get
 570 objects which are set to server 0 before from server 1, and also get objects
 571 which are set to server 1 before from server 0. If server 0 crashes,
 572 memaslap will only get objects from server 1. If server 0 comes
 573 back to life again, memaslap will reconnect server 0. If both
 574 server 0 and server 1 crash, memaslap will exit.
 575
 576
 577 Supports thousands of TCP connections
 578 _____________________________________
 579
 580
 581 Start memaslap with "--conn_sock=" or "-n" to enable this
 582 feature. Make sure that your system can tests opening thousands of files
 583 and creating thousands of sockets. However, this feature does not tests
 584 reconnection if sockets disconnect.
 585
 586 For example:
 587
 588 --threads=8 --concurrency=128 --conn_sock=128
 589
 590 The above command means that memaslap starts up 8 threads, each
 591 thread has 16 concurrencies, each concurrency has 128 TCP socket
 592 connections, and the total number of TCP socket connections is 128 \* 128 =
 593 16384.
 594
 595
 596 Supports binary protocol
 597 ________________________
 598
 599
 600 Start memaslap with "--binary" or "-B" options to enable this
 601 feature. It testss all the above features except UDP, because the latest
 602 memcached 1.3.3 does not implement binary UDP protocol.
 603
 604 For example:
 605
 606 --binary
 607
 608 Since memcached 1.3.3 doesn't implement binary UDP protocol,
 609 memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests
 610 multi-get. If you specify "--division=50" option, it just sends 50 get
 611 commands together as “mulit-get” to the server.
 612
 613
 614
 615 ------------------
 616 Configuration file
 617 ------------------
 618
 619
 620 This section describes the format of the configuration file.  By default
 621 when no configuration file is specified memaslap reads the default
 622 one located at ~/.memaslap.cnf.
 623
 624 Below is a sample configuration file:
 625
 626
 627 .. code-block:: perl
 628
 629   ---------------------------------------------------------------------------
 630   #comments should start with '#'
 631   #key
 632   #start_len end_len proportion
 633   #
 634   #key length range from start_len to end_len
 635   #start_len must be equal to or greater than 16
 636   #end_len must be equal to or less than 250
 637   #start_len must be equal to or greater than end_len
 638   #memaslap will generate keys according to the key range
 639   #proportion: indicates keys generated from one range accounts for the total
 640   generated keys
 641   #
 642   #example1: key range 16~100 accounts for 80%
 643   #          key range 101~200 accounts for 10%
 644   #          key range 201~250 accounts for 10%
 645   #          total should be 1 (0.8+0.1+0.1 = 1)
 646   #
 647   #          16 100 0.8
 648   #          101 200 0.1
 649   #          201 249 0.1
 650   #
 651   #example2: all keys length are 128 bytes
 652   #
 653   #          128 128 1
 654   key
 655   128 128 1
 656   #value
 657   #start_len end_len proportion
 658   #
 659   #value length range from start_len to end_len
 660   #start_len must be equal to or greater than 1
 661   #end_len must be equal to or less than 1M
 662   #start_len must be equal to or greater than end_len
 663   #memaslap will generate values according to the value range
 664   #proportion: indicates values generated from one range accounts for the
 665   total generated values
 666   #
 667   #example1: value range 1~1000 accounts for 80%
 668   #          value range 1001~10000 accounts for 10%
 669   #          value range 10001~100000 accounts for 10%
 670   #          total should be 1 (0.8+0.1+0.1 = 1)
 671   #
 672   #          1 1000 0.8
 673   #          1001 10000 0.1
 674   #          10001 100000 0.1
 675   #
 676   #example2: all value length are 128 bytes
 677   #
 678   #          128 128 1
 679   value
 680   2048 2048 1
 681   #cmd
 682   #cmd_type cmd_proportion
 683   #
 684   #currently memaslap only testss get and set command.
 685   #
 686   #cmd_type
 687   #set     0
 688   #get     1
 689   #
 690   #example: set command accounts for 50%
 691   #         get command accounts for 50%
 692   #         total should be 1 (0.5+0.5 = 1)
 693   #
 694   #         cmd
 695   #         0    0.5
 696   #         1    0.5
 697   cmd
 698   0    0.1
 699   1.0 0.9
 700
 701
 702
 703 ----------------
 704 Format of output
 705 ----------------
 706
 707
 708 At the beginning, memaslap displays some configuration information as follows:
 709
 710
 711 servers : 127.0.0.1:11211
 712
 713
 714
 715 threads count: 1
 716
 717
 718
 719 concurrency: 16
 720
 721
 722
 723 run time: 20s
 724
 725
 726
 727 windows size: 10k
 728
 729
 730
 731 set proportion: set_prop=0.10
 732
 733
 734
 735 get proportion: get_prop=0.90
 736
 737
 738
 739 Where
 740 _____
 741
 742
 743
 744 servers : "servers"
 745
 746  The servers used by memaslap.
 747
 748
 749
 750 threads count
 751
 752  The number of threads memaslap runs with.
 753
 754
 755
 756 concurrency
 757
 758  The number of concurrencies memaslap runs with.
 759
 760
 761
 762 run time
 763
 764  How long to run memaslap.
 765
 766
 767
 768 windows size
 769
 770  The task window size of each concurrency.
 771
 772
 773
 774 set proportion
 775
 776  The proportion of set command.
 777
 778
 779
 780 get proportion
 781
 782  The proportion of get command.
 783
 784
 785
 786 The output of dynamic statistics is something like this:
 787
 788
 789 .. code-block:: perl
 790
 791   ---------------------------------------------------------------------------------------------------------------------------------
 792   Get Statistics
 793   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 794   Avg(us)  Std_dev    Geo_dist
 795   Period   5   345826  69165     65.3      0         27      2198     203
 796   95.43      177.29
 797   Global  20  1257935  62896     71.8      0         26      3791     224
 798   117.79     192.60
 799
 800
 801   Set Statistics
 802   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 803   Avg(us)  Std_dev    Geo_dist
 804   Period   5    38425   7685      7.3       0         42      628     240
 805   88.05      220.21
 806   Global   20   139780  6989      8.0       0         37      3790    253
 807   117.93     224.83
 808
 809
 810   Total Statistics
 811   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 812   Avg(us)  Std_dev    Geo_dist
 813   Period   5   384252   76850     72.5      0        27      2198     207
 814   94.72      181.18
 815   Global  20  1397720   69886     79.7      0        26      3791     227
 816   117.93     195.60
 817   ---------------------------------------------------------------------------------------------------------------------------------
 818
 819
 820
 821 Where
 822 _____
 823
 824
 825
 826 Get Statistics
 827
 828  Statistics information of get command
 829
 830
 831
 832 Set Statistics
 833
 834  Statistics information of set command
 835
 836
 837
 838 Total Statistics
 839
 840  Statistics information of both get and set command
 841
 842
 843
 844 Period
 845
 846  Result within a period
 847
 848
 849
 850 Global
 851
 852  Accumulated results
 853
 854
 855
 856 Ops
 857
 858  Total operations
 859
 860
 861
 862 TPS
 863
 864  Throughput, operations/second
 865
 866
 867
 868 Net
 869
 870  The rate of network
 871
 872
 873
 874 Get_miss
 875
 876  How many objects can’t be gotten
 877
 878
 879
 880 Min
 881
 882  The minimum response time
 883
 884
 885
 886 Max
 887
 888  The maximum response time
 889
 890
 891
 892 Avg:
 893
 894  The average response time
 895
 896
 897
 898 Std_dev
 899
 900  Standard deviation of response time
 901
 902
 903
 904 Geo_dist
 905
 906  Geometric distribution based on natural exponential function
 907
 908
 909
 910 At the end, memaslap will output something like this:
 911
 912
 913 .. code-block:: perl
 914
 915    ---------------------------------------------------------------------------------------------------------------------------------
 916    Get Statistics (1257956 events)
 917      Min:        26
 918      Max:      3791
 919      Avg:       224
 920      Geo:    192.60
 921      Std:    116.23
 922                      Log2 Dist:
 923                        4:        0       10    84490   215345
 924                        8:   484890   459823    12543      824
 925                       12:       31
 926
 927     Set Statistics (139782 events)
 928        Min:        37
 929        Max:      3790
 930        Avg:       253
 931        Geo:    224.84
 932        Std:    116.83
 933        Log2 Dist:
 934          4:        0        0     4200 16988
 935          8:    50784    65574 2064      167
 936          12:        5
 937
 938      Total Statistics (1397738 events)
 939          Min:        26
 940          Max:      3791
 941          Avg:       227
 942          Geo:    195.60
 943          Std:    116.60
 944          Log2 Dist:
 945            4:        0       10    88690   232333
 946            8:   535674   525397    14607      991
 947            12:       36
 948
 949    cmd_get: 1257969
 950    cmd_set: 139785
 951    get_misses: 0
 952    verify_misses: 0
 953    verify_failed: 0
 954    expired_get: 0
 955    unexpired_unget: 0
 956    written_bytes: 242516030
 957    read_bytes: 1003702556
 958    object_bytes: 152086080
 959    packet_disorder: 0
 960    packet_drop: 0
 961    udp_timeout: 0
 962
 963    Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
 964    ---------------------------------------------------------------------------------------------------------------------------------
 965
 966
 967
 968 Where
 969 _____
 970
 971
 972
 973 Get Statistics
 974
 975  Get statistics of response time
 976
 977
 978
 979 Set Statistics
 980
 981  Set statistics of response time
 982
 983
 984
 985 Total Statistics
 986
 987  Both get and set statistics of response time
 988
 989
 990
 991 Min
 992
 993  The accumulated and minimum response time
 994
 995
 996
 997 Max
 998
 999  The accumulated and maximum response time
1000
1001
1002
1003 Avg
1004
1005  The accumulated and average response time
1006
1007
1008
1009 Std
1010
1011  Standard deviation of response time
1012
1013
1014
1015 Log2 Dist
1016
1017  Geometric distribution based on logarithm 2
1018
1019
1020
1021 cmd_get
1022
1023  Total get commands done
1024
1025
1026
1027 cmd_set
1028
1029  Total set commands done
1030
1031
1032
1033 get_misses
1034
1035  How many objects can’t be gotten from server
1036
1037
1038
1039 verify_misses
1040
1041  How many objects need to verify but can’t get them
1042
1043
1044
1045 verify_failed
1046
1047  How many objects with insistent value
1048
1049
1050
1051 expired_get
1052
1053  How many objects are expired but we get them
1054
1055
1056
1057 unexpired_unget
1058
1059  How many objects are unexpired but we can’t get them
1060
1061
1062
1063 written_bytes
1064
1065  Total written bytes
1066
1067
1068
1069 read_bytes
1070
1071  Total read bytes
1072
1073
1074
1075 object_bytes
1076
1077  Total object bytes
1078
1079
1080
1081 packet_disorder
1082
1083  How many UDP packages are disorder
1084
1085
1086
1087 packet_drop
1088
1089  How many UDP packages are lost
1090
1091
1092
1093 udp_timeout
1094
1095  How many times UDP time out happen
1096
1097
1098
1099 Run time
1100
1101  Total run time
1102
1103
1104
1105 Ops
1106
1107  Total operations
1108
1109
1110
1111 TPS
1112
1113  Throughput, operations/second
1114
1115
1116
1117 Net_rate
1118
1119  The average rate of network
1120
1121
1122
1123
1124
1125 -------
1126 OPTIONS
1127 -------
1128
1129
1130 -s, --servers=
1131     List one or more servers to connect. Servers count must be less than
1132     threads count. e.g.: --servers=localhost:1234,localhost:11211
1133
1134 -T, --threads=
1135     Number of threads to startup, better equal to CPU numbers. Default 8.
1136
1137 -c, --concurrency=
1138     Number of concurrency to simulate with load. Default 128.
1139
1140 -n, --conn_sock=
1141     Number of TCP socks per concurrency. Default 1.
1142
1143 -x, --execute_number=
1144     Number of operations(get and set) to execute for the
1145     given test. Default 1000000.
1146
1147 -t, --time=
1148     How long the test to run, suffix: s-seconds, m-minutes, h-hours,
1149     d-days e.g.: --time=2h.
1150
1151 -F, --cfg_cmd=
1152     Load the configure file to get command,key and value distribution list.
1153
1154 -w, --win_size=
1155     Task window size of each concurrency, suffix: K, M e.g.: --win_size=10k.
1156     Default 10k.
1157
1158 -X, --fixed_size=
1159     Fixed length of value.
1160
1161 -v, --verify=
1162     The proportion of date verification, e.g.: --verify=0.01
1163
1164 -d, --division=
1165     Number of keys to multi-get once. Default 1, means single get.
1166
1167 -S, --stat_freq=
1168     Frequency of dumping statistic information. suffix: s-seconds,
1169     m-minutes, e.g.: --resp_freq=10s.
1170
1171 -e, --exp_verify=
1172     The proportion of objects with expire time, e.g.: --exp_verify=0.01.
1173     Default no object with expire time
1174
1175 -o, --overwrite=
1176     The proportion of objects need overwrite, e.g.: --overwrite=0.01.
1177     Default never overwrite object.
1178
1179 -R, --reconnect
1180     Reconnect tests, when connection is closed it will be reconnected.
1181
1182 -U, --udp
1183     UDP tests, default memaslap uses TCP, TCP port and UDP port of
1184     server must be same.
1185
1186 -a, --facebook
1187     Whether it enables facebook test feature, set with TCP and multi-get with UDP.
1188
1189 -B, --binary
1190     Whether it enables binary protocol. Default with ASCII protocol.
1191
1192 -P, --tps=
1193     Expected throughput, suffix: K, e.g.: --tps=10k.
1194
1195 -p, --rep_write=
1196     The first nth servers can write data, e.g.: --rep_write=2.
1197
1198 -b, --verbose
1199     Whether it outputs detailed information when verification fails.
1200
1201 -h, --help
1202     Display this message and then exit.
1203
1204 -V, --version
1205     Display the version of the application and then exit.
1206
1207
1208 --------
1209 EXAMPLES
1210 --------
1211
1212
1213 memaslap -s 127.0.0.1:11211 -S 5s
1214
1215 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
1216
1217 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
1218
1219 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
1220
1221 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
1222
1223 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
1224
1225 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
1226
1227
1228 ----
1229 HOME
1230 ----
1231
1232
1233 To find out more information please check:
1234 `http://libmemcached.org/ <http://libmemcached.org/>`_
1235
1236
1237 -------
1238 AUTHORS
1239 -------
1240
1241
1242 Mingqiang Zhuang <mingqiangzhuang@hengtiansoft.com> (Schooner Technolgy)
1243 Brian Aker, <brian@tangent.org>
1244
1245
1246 --------
1247 SEE ALSO
1248 --------
1249
1250 :manpage:`memcached(1)` :manpage:`libmemcached(3)`